Question for the math geniuses (trig)

[McLaren]

Good morning everyone, I have a problem I hope you can help me solve. I am trying to find the difference in rotation between two triangles, but I am only coming up with two answers, when I should have 4. The first triangle is a right triangle used for my reference. The angle goes up and to the right. The location of the top right corner is X34, Y10. So I am using tan-1(10/34) and getting 16.389 which is great. The next triangle changes based on how the part is loaded, but for simplicities sake rotate 0,90,180,270(counter clockwise). At zero the difference ends up being zero, at 90 it's -90, at 180 it's 0, at 270 it's -90.

Thank you in advance for any and all replies.

 

[McLaren]

That post seems confusing. The second triangle is the same exact triangle, just rotated around X0,Y0. I don't know how much it is rotated, just the location of the top right corner. My formula was tan-1(new"Y"/new"X")-tan-1(10/34).

 

[enXLS]

I can help but I cant understand your question. I can picture your first triangle but could you clarify what you are doing to the triangle and what you then want to caculate.

 

[Oaktree]

IMO, the easiest way to calculate this is to first convert to polar coordinates.

See:
http://en.wikipedia.org/wiki/Polar_coordinate_system

for how to convert from cartesian coordinates <-->polar coordinates